Drawing instrument.



PATENTED APR.- 30, l907 H. MBT'ILER. DRAWING INSTRUMENT. APPLIOATION FILED JUNE 2a. 190s.

OMI/SM1 HANS METTLER, OF AARAU, SWITZERLAND.

DRAWING INSTRUMENT.

Specification of Letters Patent.

Patented Apr-n 3o, 1907'.

Application filed June 28, 1906. Serial No. 323,948.

Beit known that I, HANS MET'iLnn, a citi- Zen of Switzerland, residing in Aarau, in the canton of Aargau, Republic of Switzerland, (whose post-office address is 1407 Entfelderstrasse, Aaratn) have invented certain new and useful Improvements in Drawing Instruments and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters of reference marked thereon, which form a part of this specification.

In the drawing instrument herewith described with spring jaws and means for adjusting the same, each aw has a wedgeshaped part and there is a piece which by action upon the wedge-shaped parts imposes to the jaws a movement opposite to that due to the spring action of the jaws.

The annexed drawing shows a fountain ruling pen as one form ot' construction of the new instrument.

Figure l is a longitudinal vertical section, Fig. 2 is partly a longitudinal horizontal section and partly a plan. Fig. 3 is an elevation showiiig the instrument in open position. Fig. 4 and 5 are cross sections on lines A--B and (1*D in Fig. l and 2.

A is the coupling sleeve having an outer screw thread by means of which the sleeve can be screwed into the ink holding pen holder. The sleeve A has also an inner screw thread into which is screwed a tube B which surrounds the ink feeding tube C.

D is the ruling pen carried by the tube B and held thereupon by frictional contact. The jaws D of the pen have the tendency to open themselves by elasticity. Each of the jaws has a wedge shaped part d and two lateral notches d1 giving the jaw the required elasticity. The rear cylindrical part of the pen has a screw thread (Z2 on its periphery upon which thread the rear end of the threaded sleeve E is screwed. The front part of the sleeve E is fitted on its interior to the wedge shaped parts d of the aws D', the remaining portion of the bore of the sleeve being cylindrical.

In screwing up the sleeve, its front part presses upon the wedge shaped parts of the jaws, closing them opposite to the spring action of the jaws. In reversing the movement, the jaws are allowed to open, so as the same may be easily cleaned (Fig. 3).

The manipulation of the ruling penis very simple, the adjustment of the aws very accurate. No drilling and threading lof the jaws or any adjusting bolt is necessary. The jaws ofthe new drawing instrument may also be formed in such a way, that those surfaces of the wedge-shape parts upon which an opening or closing action has to take place, are on the inside of the jaws. In this ease, the piece acting upon the saidr surfaces should be placed between them and the spring action of the jaws should tend to close tho pen. In order to easily adjust the jaws to the desired thickness of lines, the cylindrical part of the ruling pen is provided with a scale D:i (Fig. 2) over which the sleeve E can move.

What I claim is In a drawing instrument of the character described, the combination with the tube B, of a ruling pen D mounted on said tube, the rear portion of said pen being provided with a scale and with an exterior screw-thread d and vthe forward end of said pen being provided wi'th spring jaws, each of which. latter has a wedge shaped portion d intermediate the scre\vntlnead and the forward end of said jaws, and a sleeve E interiorly threaded and screwing upon the screw-thread of the pen D and playing over the scale thereon, the forward end of the sleeve .E being adapted to bear upon the tapered portion of the jaws for the purpose set forth.

In testimony whereof, I have signed my name to this specification in the presence of two subscribing witnesses:

HANS METTIJER.

Vitnesses:

HERMANN HUBER, A. LIEBERKNECHT. 

